Stock Options, Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unamortized Stock Compensation Expense [Abstract]
Unamortized stock compensation expense	$ 9,377,425
Period for recognition	1 year 5 months 12 days
Equity Compensation Plans [Member] | Qualified and Nonqualified Stock Options [Member]
Number of Shares [Roll Forward]
Options outstanding, beginning balance (in shares)	2,445,711	1,993,301	1,430,111
Granted (in shares)	1,902,609	452,410	563,190
Exercised (in shares)	(4,753)	0	0
Forfeited (in shares)	(30,640)	0	0
Expirations (in shares)	(10,660)
Options outstanding, ending balance (in shares)	4,302,267	2,445,711	1,993,301
Vested and expected to vest (in shares)	4,213,091	2,408,395	1,942,840
Exercisable (in shares)	1,857,077	1,413,335	915,592
Weighted Average Exercise Price [Roll Forward]
Options outstanding, beginning balance (in dollars per share)	$ 3.13	$ 2.00	$ 1.98
Granted (in dollars per share)	7.87	8.15	2.04
Exercised (in dollars per share)	0.23	0	0
Forfeited (in dollars per share)	7.98	0	0
Expirations (in dollars per share)	8.28
Options outstanding, ending balance (in dollars per share)	5.19	3.13	2.00
Vested and expected to vest (in dollars per share)	5.14	3.12	2.00
Exercisable (in dollars per share)	$ 2.83	$ 2.46	$ 1.85
Remaining Contractual Life and Aggregate Intrinsic Value [Abstract]
Options outstanding, weighted average remaining contractual life	8 years 1 month 20 days	8 years 2 months 5 days	8 years 11 months 5 days
Options outstanding, aggregate intrinsic value	$ 31,659,550	$ 6,247,407	$ 2,238,711
Vested and expected to vest, weighted average contractual life	8 years 1 month 13 days	8 years 2 months 1 day	8 years 11 months 1 day
Vested and expected to vest, aggregate intrinsic value	$ 31,202,132	$ 6,175,025	$ 2,190,292
Exercisable, weighted average contractual life	7 years 18 days	7 years 10 months 10 days	8 years 5 months 26 days
Exercisable, aggregate intrinsic value	$ 17,952,965	$ 4,162,373	$ 1,168,240